The steel industry has a substantial and growing need for addition agents for producing high strength steel alloys. Various metal carbides have been utilized for this purpose in the past. For example, U.S. Pat. No. 3,334,992 describes the vanadium containing addition agents V.sub.2 C and VC and a method for their preparation which involves reduction of vanadium trioxide with carbon at high temperatures under a vacuum. This patent also describes a process in which small amounts of iron powder may be blended with the vanadium trioxide prior to the reduction to increase the strength and reduce the oxygen and nitrogen content of the vanadium carbide addition agent. U.S. Pat. No. 3,342,553 describes a multistage process in which a vanadium carbide addition agent is prepared by sequentially reducing vanadium pentoxide to tetroxide and then to a vanadium oxycarbide. The vanadium oxycarbide is then further reduced with carbon in a vacuum furnace to produce the desired vanadium carbide. Both processes are undesirable since the vanadium carbide agents must be prepared under vacuum conditions which are difficult and expensive to maintain in large scale production. U.S. Pat. No. 3,504,093 describes a columnar furnace designed for the continuous production of metal carbide products in which agglomerates of carbon and a metal oxide such as vanadium oxide are heated to a temperature between 1500.degree. and 1900.degree.C. to produce the metal carbide and then immediately cooled in a cooling zone of the furnace to a temperature of about 400.degree.C.
It is an object of this invention to prepare carbide addition agents in a relatively simple manner which does not require the use of vacuum conditions but which provides addition agents of excellent quality.
It is a further object of this invention to prepare carbide addition agents which readily combine with molten iron and steel to produce high strength alloys.